Pixel structure for transflective LCD panel and fabricating method thereof

ABSTRACT

A pixel structure for a transflective LCD having a transparent region and a reflective region is provided. The pixel structure includes a transparent substrate, a TFT, at least one reflective structure, a passivation layer, a pixel electrode and a reflective layer. The TFT is disposed in a reflective region of the transparent substrate. The reflective structure is configured at one side of the TFT, and located in the reflective region of the transparent substrate. The passivation layer is disposed over the transparent substrate and covers the TFT and the reflective structure. The pixel electrode is disposed above the TFT and the reflective structure, and is at least located in a transparent region. The pixel electrode is electrically connected to the TFT. The reflective layer is disposed above the TFT and the reflective structure, and is located in the reflective region.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 94131048, filed on Sep. 9, 2005. All disclosure of the Taiwanapplication is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pixel structure and a fabricatingmethod thereof, and particularly to a pixel structure for atransflective thin film transistor (TFT) liquid crystal display (LCD)for improving efficiency in backlight utilization and a fabricatingmethod thereof.

2. Description of Related Art

Since the first cathode ray tube (CRT) television was invented, displaytechnology has developed rapidly. However, CRT displays have obviousdisadvantages such as large size, heavy weight, high radiation and poorpixel quality, and therefore various flat display panels are exploredand introduced. Among them, LCDs, with advantages such as compact size,power consumption, no radiation, full color display, and portability,have become the most developed and popular products. LCDs are used invarious applications including cellular phone, electronic dictionary,digital camera, digital camcorder, personal digital assistant, notebookcomputer and desktop computer.

TFT LCDs can be generally categorized into transmissive type, reflectivetype and transflective type, according to the light source and arraysubstrates used. A typical transmissive TFT LCD uses a backlight source,and employs transparent electrodes as pixel electrodes of the TFT arraysubstrate for allowing backlights to transmit through. A typicalreflective TFT LCD uses a front-light source and/or ambient lights as alight source, and employs metal or other reflective material asreflective electrodes for reflecting the front-lights or the ambientlights. A typical transflective TFT LCD can be viewed as a combinationof a transmissive TFT LCD and a reflective TFT LCD, taking advantages ofthe backlight source and the front-light source or the ambient lightsfor display.

In the conventional transflective TFT LCDs, the reflective layers areusually designed to have rough surfaces for obtaining widely distributedreflected lights. However, the process to make the surfaces roughincreases production costs. Further, when the backlight source providesbacklights for display, only those radiating on the transparentelectrodes rather than those radiating on the reflective layer can beused. Therefore, such a conventional transflective TFT LCD has lowerutilization efficiency of lights provided by the backlight module.

SUMMARY OF THE INVENTION

Therefore, an object of the invention is to provide a pixel structurefor a transflective TFT LCD panel, adapted for improving efficiency inbacklights utilization of the TFT LCD.

Another object of the invention is to provide a method for fabricating atransflective TFT LCD panel having higher efficiency in backlightsutilization.

According to the foregoing objects and others, the present inventionprovides a pixel structure for a transflective TFT LCD. The pixelstructure includes a transparent substrate, a TFT, at least onereflective structure, a passivation layer, a pixel electrode and areflective layer. The TFT is disposed in a reflective region of thetransparent substrate. The reflective structure is configured at oneside of the TFT and located in the reflective region of the transparentsubstrate. The passivation layer is disposed over the transparentsubstrate and covers the TFT and the reflective structure. The pixelelectrode is disposed above the TFT and the reflective structure, and atleast is located in a transparent region. The pixel electrode iselectrically connected to the TFT. The reflective layer is disposedabove the TFT and the reflective structure, and is located in thereflective region.

According to an embodiment of the pixel structure for a transflectiveTFT LCD panel, the TFT includes a gate electrode, a gate insulatinglayer, a semiconductor layer and a source/drain electrode. The gateelectrode is disposed on the transparent substrate. The gate insulatinglayer is also disposed over the transparent substrate and covers thegate electrode. The semiconductor layer is disposed on the gateinsulating layer and above the gate electrode. The source/drainelectrode is disposed on the semiconductor layer and above the gateelectrode.

According to an embodiment of the pixel structure for a transflectiveTFT LCD panel, the reflective structure includes a first metallic layer.The first metallic layer and the gate electrode are of a same filmlayer, for example. The first metallic layer is lodged into a depressionof or protrudes from the transparent substrate surface, for example.Furthermore, the gate insulating layer extends outside the TFT forexample, and covers the first metallic layer.

According to an embodiment of the pixel structure for a transflectiveTFT LCD panel, the first metallic layer and the source/drain electrodefor example are of a same layer. The gate insulating layer for exampleextends outside the TFT and is disposed between the first metallic layerand the transparent substrate. The first metallic layer for example islodged in a depression of the gate insulating layer surface.

According to an embodiment of the pixel structure for a transflectiveTFT LCD panel, the reflective structure for example further includes asecond metallic layer. The second metallic layer is disposed on thefirst metallic layer. The first metallic layer and the gate electrodefor example are of a same film layer, and the second metallic layer andthe source/drain electrode for example are of a same layer. Furthermore,the gate insulating layer for example extends outside the TFT, and thegate insulating layer for example is disposed between the first metalliclayer and the second metallic layer.

According to an embodiment of the pixel structure for a transflectiveTFT LCD panel, the reflective structure is sawtooth-shaped orblock-shaped.

According to an embodiment of the invention, the pixel structure for atransflective TFT LCD panel further includes a flatting layer, disposedbetween the pixel electrode and the transparent substrate, and coveringthe TFT and the reflective structure.

The present invention further provides a method for fabricating a pixelstructure for a transflective LCD panel. The fabricating method includesthe steps of: providing a transparent substrate; then forming a TFT andconfiguring a reflective structure on the transparent substrate, whereinthe reflective structure is located at one side of the TFT; forming apassivation layer over the transparent substrate, wherein thepassivation layer covers the TFT and the reflective structure; forming apixel electrode above the TFT and the reflective structure, wherein thepixel electrode and the TFT are electrically connected to each other;then forming a reflective layer above the TFT and the reflectivestructure.

According to an embodiment of the method for fabricating a pixelstructure for a transflective LCD panel, the step of forming areflective structure for example includes forming a first metallic layeron the transparent substrate, wherein the first metallic layer forexample is formed simultaneously with the gate electrode. Further,before the first metallic is formed, a lithographic process and anetching process are performed on the transparent substrate to form afirst depression, the first depression being adapted for receiving thefirst metallic layer. Also, the gate insulating layer for example coversthe first metallic layer.

According to an embodiment of the method for fabricating a pixelstructure for a transflective LCD panel, the method of forming areflective structure for example is by forming a first metallic layer onthe transparent substrate, simultaneously with the gate electrode.Further, before forming the first metallic layer, the method includesconducting a lithographic process and an etching process to form a firstdepression for receiving the metallic layer therein; and thereafter,forming the gate insulating layer covering the first metallic layer.

According to an embodiment of the method for fabricating a pixelstructure for a transflective LCD panel, the first metallic layer forexample is formed simultaneously with the source/drain electrode.Further, before the first metallic layer is formed, a lithographicprocess and an etching process are performed on the gate insulatinglayer to form a second depression, the second depression being adaptedfor receiving the first metallic layer.

According to an embodiment of the method for fabricating a pixelstructure for a transflective LCD panel, the step of forming areflective structure for example further includes forming a secondmetallic layer above the first metallic layer. The first metallic layerfor example is simultaneously formed with the gate electrode, and thesecond metallic layer for example is simultaneously formed with thesource/drain electrode. Further, before the first metallic layer and thegate electrode are formed, a lithographic process and an etching processare performed on the transparent substrate to form a first depression,the first depression being adapted for receiving the first metalliclayer. Furthermore, after the gate insulating layer is formed and beforethe second metallic layer is formed, a lithographic process and anetching process are performed on the gate insulating layer to form asecond depression, the second depression being adapted for receiving thesecond metallic layer.

According to an embodiment of the invention, after the passivation layeris formed and before the pixel electrode is formed, a flatting layer isformed for covering the TFT and the reflective structure.

When forming a TFT, a reflective structure is simultaneously formed onat least one side of the TFT. There is no extra processing needed toform the reflective structure. Further, this reflective structure isadapted for improving efficiency in backlights utilization of the TFTLCD.

BRIEF DESCRIPTION OF THE DRAWING

The features of the invention which are believed to be novel are setforth with particularity in the appended claims. The invention, togetherwith its objects and the advantages thereof, may be best understood byreference to the following description taken in conjunction with theaccompanying drawings, in which like reference numerals identify likeelements in the figures and in which:

FIGS. 1A through 1E schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the firstembodiment of the invention.

FIGS. 2A through 2E schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the secondembodiment of the invention.

FIGS. 3A through 3D schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the thirdembodiment of the invention.

FIGS. 4A through 4D schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the fourthembodiment of the invention.

FIGS. 5A through 5D schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the fifthembodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

The following embodiments illustrate different types of pixel structuresfor a transflective LCD. The pixel structure mainly includes atransparent substrate, a TFT, at least one reflective structure, a pixelelectrode and a reflective layer. The TFT is disposed on the transparentsubstrate, and is located in a reflective region. The reflectivestructure is configured at one side of the TFT on the transparentsubstrate, and located in the reflective region. The pixel electrode isdisposed above the TFT and the reflective structure, and at least islocated in a transparent region. The pixel electrode is electricallyconnected to the TFT. The reflective layer is disposed above the TFT andthe reflective structure, and is located in the reflective region.Detailed structures accompanying with the manufacturing process thereofwill be described in the following embodiments.

The First Embodiment

FIGS. 1A through 1E schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the firstembodiment of the invention. First, the step shown in FIG. 1A, includesproviding a transparent substrate 100, and simultaneously forming a gateelectrode 110 and a metallic layer 122 on the transparent substrate 100,wherein the metallic layer 122 is formed at one side of the gateelectrode 110 for configuring a reflective structure 120. According tothe first embodiment, the reflective structure 120 for example can beeither sawtooth-shaped or block-shaped. Further, the transparentsubstrate 100 for example is a glass substrate. The reflective structure120 and the gate electrode 110 are made of a same material.

Then, the following step shown in FIG. 1B includes forming a gateinsulating layer 130 over the transparent substrate 100 in a chemicalvapor deposition (CVD) method, for example, wherein the gate insulatinglayer 130 covers the gate electrode 110 and the reflective structure120. The gate insulating layer 130 for example is made of silicondioxide, silicon nitride or silicon oxynitride.

Then, the following step shown in FIG. 1C includes forming asemiconductor layer 140 above the gate electrode 110. The method forforming the semiconductor layer 140 includes: forming an amorphoussilicon layer 142; then forming an ohmic contact layer 144 on theamorphous silicon layer 142, wherein the ohmic contact layer 144 is madeof N+ doped amorphous silicon, for example; and thereafter, forming asource electrode 152 and a drain electrode 154. The source electrode 152and the drain electrode 154 for example are made of a material selectedfrom a group consisting of copper, tungsten, chromium, aluminum or acombination thereof. The gate electrode 110, the semiconductor layer140, the source electrode 152 and the drain electrode 154 constitute aTFT 160.

Then, the following step shown in FIG. 1D includes optionally forming apassivation layer 170 over the transparent substrate 100, thepassivation layer 170 covering the TFT 160; forming a flatting layer180; then patterning the flatting layer 180 and the passivation layer170 to form an contact hole 182 of the flatting layer 180 and thepassivation layer 170.

Then, the following step shown in FIG. 1E includes: forming a pixelelectrode 190, and forming a reflective layer 192 on the pixel electrode190. The pixel electrode 190 is electrically connected with the drainelectrode 154 via the contact hole 182 of the flatting layer 180 and thepassivation layer 170. The area of the pixel structure of thetransflective LCD panel covered by the reflective layer 192 is areflective region 101 b, and the area not covered thereby is atransparent region 101 a. According to an aspect of the embodiment, thepixel electrode 190 covers the entire flatting layer 180, whileaccording to other aspects of the embodiment, the pixel electrode 190can be located within the transparent region 101 a, being adjacent tothe reflective layer 192.

It is to be noted that the TFT 160 and the reflective structure 120 aresimultaneously configured according to the first embodiment, while inother embodiments, they are individually configured. For example, theTFT 160 is configured at first, and thereafter the reflective structure120 is configured at one side of the TFT 160, or the reflectivestructure 120 is configured at first and then the TFT 160 is configured.

According to the first embodiment, the reflective structure 120 issimultaneously formed at one side of the TFT 160, when the gateelectrode 110 is formed. In operation, a backlight module (not shown)provides a backlight, the backlight including a light L1 incident to thetransparent region 101 a and a light L2 incident to the reflectiveregion 101 b. The light L1 is adapted for passing through thetransparent region 101 a for display, and the light L2 is reflected bythe reflective layer 192 to the reflective structure 120, wherein thereflective structure 120 reflects the light L2 out of the panel.Therefore, the efficiency in backlights utilization can be improved.

The Second Embodiment

FIGS. 2A through 2E schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the secondembodiment of the invention. First, the step shown in FIG. 2A includesproviding a transparent substrate 200, conducting a lithographic processand an etching process to form a depression 202 at the surface of thetransparent substrate 200. The transparent substrate 200 for example isa glass substrate, and the etching liquid used for etching thetransparent substrate 200 for example is a hydrogen fluoride solution.

Then, the following step shown in FIG. 2B includes forming a gateelectrode 210, and at the same time forming a metallic layer 222 at oneside of the gate electrode 210, wherein the metallic layer 222 is lodgedinto the depression 202 for configuring a reflective structure 220. Itis to be noted that the reflective structure 220 and the gate electrode210 are made of a same material.

Then, the following step shown in FIG. 2C includes forming a gateinsulating layer 230 over the transparent substrate 100 by a CVD method,for example, wherein the gate insulating layer 230 covers the gateelectrode 110 and the reflective structure 120. The gate insulatinglayer 230 is made of silicon dioxide, silicon nitride, or siliconoxynitride, for example.

Then, the following step shown in FIG. 2D includes: forming asemiconductor layer 240 on the gate insulating layer 230 and above thegate electrode 210. The method for forming the semiconductor layer 240includes: forming an amorphous silicon layer 242; then forming an ohmiccontact layer 244 on the amorphous silicon layer 242, wherein the ohmiccontact layer 244 for example is made of N+ doped amorphous silicon; andthereafter, forming a source electrode 252 and a drain electrode 254.The source electrode 252 and the drain electrode 254 for example aremade of a material selected from a group consisting of copper, tungsten,chromium, aluminum or a combination thereof. The gate electrode 210, thesemiconductor layer 240, the source electrode 252 and the drainelectrode 254 constitute a TFT 260.

Then, the following step shown in FIG. 2E includes optionally forming apassivation layer 270 over the transparent substrate 200, thepassivation layer 270 covering the TFT 260; forming a flatting layer280; then patterning the flatting layer 280 and the passivation layer270 to form an contact hole 282 of the flatting layer 280 and thepassivation layer 270. The step shown in FIG. 2E further includesforming a pixel electrode 290 and forming a reflective layer 292 on thepixel electrode 290. The pixel electrode 290 is electrically connectedwith the drain electrode 254 via the contact hole 282 of the flattinglayer 280 and the passivation layer 270. The area of the pixel structureof the transflective LCD panel covered by the reflective layer 292 is areflective region 201 b, and the area not covered thereby is atransparent region 201 a. According to an aspect of the embodiment, thepixel electrode 290 covers the entire flatting layer 280, whileaccording to other aspects of the embodiment, the pixel electrode 290 islocated within the transparent region 201 a, adjacent to the reflectivelayer 292.

According to the second embodiment, a plurality of depressions 202 areformed at the surface of the transparent substrate 200 for thereflective structure 220 to be formed therein when the gate electrode210 is formed. File reflective structure 220 for example isblock-shaped. The reflective structure 220 configured at one side of theTFT 260 is adapted for improving the efficiency in backlightsutilization.

The Third Embodiment

FIGS. 3A through 3D schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the thirdembodiment of the invention. First, the step shown in FIG. 3A includesproviding a transparent substrate 300, and forming gate electrode 310 onthe transparent substrate 300.

Then, the following step shown in FIG. 3B includes: forming a gateinsulating layer 330 over the transparent substrate 300 by a CVD method,for example, wherein the gate insulating layer 330 covers the gateelectrode 310; and forming a semiconductor layer 340 above the gateinsulating layer 330. The gate insulating layer 330 for example is madeof silicon dioxide, silicon nitride or silicon oxynitride. The methodfor forming the semiconductor layer 340 includes: forming an amorphoussilicon layer 342; then forming an ohmic contact layer 344 on theamorphous silicon layer 342, wherein the ohmic contact layer 344 forexample is made of N+ doped amorphous silicon.

Then, the following step shown in FIG. 3C, includes: forming a sourceelectrode 352, a drain electrode 354, and at the same time forming ametallic layer 322 at one side of the source electrode 352 and the drainelectrode 322. The gate electrode 310, the semiconductor layer 340, thesource electrode 352 and the drain electrode 354 constitute a TFT 360,and the metallic layer 322 functions as a reflective structure 320. Thereflective structure 320 for example is sawtooth-shaped or block-shaped.Further, the reflective structure 320, the source electrode 352 and thedrain electrode 354 are made of a same material.

Then, the following step shown in FIG. 3D, includes: optionally forminga passivation layer 370 over the transparent substrate 300, thepassivation layer 370 covering the TFT 360 and the metallic layer 322;forming a flatting layer 380; then patterning the flatting layer 380 andthe passivation layer 370 to form an contact hole 382 of the flattinglayer 380 and the passivation layer 370. The step shown in FIG. 3Dfurther includes forming a pixel electrode 390, and forming a reflectivelayer 392 on the pixel electrode 390. The pixel electrode 390 iselectrically connected with the drain electrode 354 via the contact hole382 of the flatting layer 380 and the passivation layer 370. The area ofthe pixel structure of the transflective LCD panel covered by thereflective layer 392 is a reflective region 301 b, and the area notcovered thereby is a transparent region 301 a. According to an aspect ofthe embodiment, the pixel electrode 390 covers the entire flatting layer380, while according to other aspects of the embodiment, the pixelelectrode 390 is located within the transparent region 301 a, adjacentto the reflective layer 392.

According to the third embodiment, a reflective structure 320 isconfigured on the gate insulating layer 330 at one side of the TFT 360,when the source electrode 352 and the drain electrode 354 are formed.The reflective structure 320 is adapted for improving the efficiency inbacklights utilization.

The Fourth Embodiment

FIGS. 4A through 4D schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the fourthembodiment of the invention. First, the step shown in FIG. 4A includesproviding a transparent substrate 400, and forming gate electrode 410 onthe transparent substrate 400.

Then, the following step shown in FIG. 4B includes: forming a gateinsulating layer 430 over the transparent substrate 400 by a CVD method,for example, wherein the gate insulating layer 430 covers the gateelectrode 410; and forming a semiconductor layer 440 above the gateinsulating layer 430. The gate insulating layer 430 for example is madeof silicon dioxide, silicon nitride or silicon oxynitride. The methodfor forming the semiconductor layer 440 includes: forming an amorphoussilicon layer 442; then forming an ohmic contact layer 444 on theamorphous silicon layer 442, wherein the ohmic contact layer 444 forexample is made of N+ doped amorphous silicon.

Then, the following step shown in FIG. 4C, includes: conducting alithographic process and an etching process to form a depression 432 onthe gate insulating layer 430; then simultaneously forming a sourceelectrode 452, a drain electrode 454 and a metallic layer 422, whereinthe source electrode 452 and the drain electrode 454 are located on thegate electrode 410, and the metallic layer 422 is lodged in thedepression 432 for configuring a reflective structure 420. The gateelectrode 410, the semiconductor layer 440, the source electrode 452 andthe drain electrode 454 constitute a TFT 460. The reflective structure420 for example is sawtooth-shaped or block-shaped. Further, thereflective structure 420, the source electrode 420 and the drainelectrode 454 are made of a same material.

Then, the following step shown in FIG. 4D includes: optionally forming apassivation layer 470 over the transparent substrate 400, thepassivation layer 470 covering the TFT 460 and the metallic layer 422;forming a flatting layer 480; then patterning the flatting layer 480 andthe passivation layer 470 to form an contact hole 482 of the flattinglayer 480 and the passivation layer 470. The step shown in FIG. 4Dfurther includes forming a pixel electrode 490, and forming a reflectivelayer 492 on the pixel electrode 490. The pixel electrode 490 iselectrically connected with the drain electrode 454 via the contact hole482 of the flatting layer 480 and the passivation layer 470. The area ofthe pixel structure of the transflective LCD panel covered by thereflective layer 492 is a reflective region 401 b, and the area notcovered thereby is a transparent region 401 a. According to an aspect ofthe embodiment, the pixel electrode 490 covers the entire flatting layer480, while according to other aspects of the embodiment, the pixelelectrode 490 is located within the transparent region 401 a, adjacentto the reflective layer 492.

According to the third embodiment, the depression 432 is formed on thegate insulating layer 430 for configuring a reflective structure 420lodged in the depression 432 of the gate insulating layer 430 at oneside of the TFT 460, when the source electrode 452 and the drainelectrode 454 are formed. The reflective structure 420 is adapted forimproving the efficiency in backlights utilization.

The Fifth Embodiment

FIGS. 5A through 5D schematically illustrate a flow chart of fabricatinga pixel structure for a transflective LCD panel, according to the fifthembodiment of the invention. First, the step shown in FIG. 5A includesproviding a transparent substrate 500, and forming gate electrode 510and a metallic layer 522 on the transparent substrate 500, wherein themetallic layer 522 is located at one side of the gate electrode 510.According to an aspect of the embodiment, a method for forming themetallic layer 522 is by directly forming a patterned metallic layer onthe transparent substrate 500 as shown in FIG. 1. Another method forforming the metallic layer 522 can be, as shown in FIG. 2, by conductinga lithographic process and an etching process to form a depression (notshown) for receiving the metallic layer 522 when forming the gateelectrode 510.

Then, the following step shown in FIG. 5B includes: forming a gateinsulating layer 530 over the transparent substrate 500 by a CVD method,for example, wherein the gate insulating layer 530 covers the gateelectrode 510 and the metallic layer 522; and forming a semiconductorlayer 540 on the gate insulating layer 530 and above the gate electrode510. The gate insulating layer 530 for example is made of silicondioxide, silicon nitride or silicon oxynitride. The method for formingthe semiconductor layer 540 includes: forming an amorphous silicon layer542; then forming an ohmic contact layer 544, wherein the ohmic contactlayer 544 for example is made of N+ doped amorphous silicon.

Then, the following step shown in FIG. 5C includes: forming a sourceelectrode 552, a drain electrode 554, and at the same time forming ametallic layer 522, wherein the source electrode 552 and the drainelectrode 554 are above the gate electrode 510, and the metallic layer524 is above the metallic layer 522. The gate electrode 510, thesemiconductor layer 540, the source electrode 552 and the drainelectrode 554 constitute a TFT 560, and the metallic layer 522 and themetallic layer 524 function as a reflective structure 320. Further, themetallic layer 522 and the gate electrode 510 are made of a samematerial, while the metallic layer 524 and the source electrode 552, thedrain electrode 554 are made of a same material. The metallic layer 522and the metallic layer 524 for example are sawtooth-shaped orblock-shaped.

Moreover, according to the embodiment, the method for forming themetallic layer 524 can also be, as shown in FIG. 4, by conducting alithographic process and an etching process to form a depression (notshown) on the gate insulating layer 530, and then simultaneously formingthe source electrode 552, the drain electrode 554 and the metallic layer524, for receiving the metallic layer 524 in the depression.

Then, the following step shown in FIG. 5D includes: optionally forming apassivation layer 570 over the transparent substrate 500, thepassivation layer 570 covering the TFT 560 and the metallic layer 522;forming a flatting layer 580; then patterning the flatting layer 580 andthe passivation layer 570 to form an contact hole 582 of the flattinglayer 580 and the passivation layer 570. The step shown in FIG. 5Dfurther includes forming a pixel electrode 590, and forming a reflectivelayer 592 on the pixel electrode 590. The pixel electrode 590 iselectrically connected with the drain electrode 554 via the contact hole582 of the flatting layer 580 and the passivation layer 570. The area ofthe pixel structure of the transflective LCD panel covered by thereflective layer 592 is a reflective region 501 b, and the area notcovered thereby is a transparent region 501 a. According to an aspect ofthe embodiment, the pixel electrode 590 covers the entire flatting layer580, while according to other aspects of the embodiment, the pixelelectrode 590 is located within the transparent region 501 a, adjacentto the reflective layer 592.

According to the fifth embodiment, the reflective structure 520 forexample is a dual-layer structure configured simultaneously with thegate electrode 510, the source electrode 522 and the drain electrode554. The reflective structure 520 is located at one side of the TFT 560for improving the efficiency in backlights utilization.

According to the above-described embodiments, combined with an opticalmask processing, the present invention is adapted for fabricating areflective structure at one side of a TFT, for improving the efficiencyin backlights utilization. The reflective structure can be formedsimultaneously with the gate, and can either protrude from or lodge intothe substrate surface. Further, the reflective structure can also beformed simultaneously with the source/drain electrode, and can eitherprotrude from or lodge into the substrate surface. Furthermore, thereflective structure can also be a dual-layer structure, or even acombination of the above-mentioned types.

In summary, the pixel structure for a transflective LCD panel and thefabricating method thereof according to the present invention have atleast the following advantages and features:

-   1. A reflective structure is disposed on at least one side of the    TFT, thus improving the efficiency in backlights utilization;-   2. The reflective structure is formed at one side of the TFT while    the TFT is formed, thereby excluding additional optical masks and    process, and saving production cost.

Other modifications and adaptations of the above-described preferredembodiments of the present invention may be made to meet particularrequirements. This disclosure is intended to exemplify the inventionwithout limiting its scope. All modifications that incorporate theinvention disclosed in the preferred embodiment are to be construed ascoming within the scope of the appended claims or the range ofequivalents to which the claims are entitled.

1. A pixel structure for a transflective LCD having a transparent regionand a reflective region, the pixel structure comprising: a transparentsubstrate, a TFT, disposed in the reflective region of the transparentsubstrate; at least one reflective structure, configured at one side ofthe TFT on the transparent substrate, and located in the reflectiveregion of the transparent substrate; a passivation layer, disposed overthe transparent substrate and covering the TFT and the reflectivestructure; a pixel electrode, disposed above the TFT and the reflectivestructure, and at least located in the transparent region, the pixelelectrode being electrically connected to the TFT; and a reflectivelayer, disposed above the TFT and the reflective structure, and locatedin the reflective region.
 2. The pixel structure according to claim 1,wherein the TFT comprises: a gate electrode, a gate insulating layer,disposed over the transparent substrate and covering the gate electrode;a semiconductor layer, disposed on the gate insulating layer and abovethe gate electrode; and a source/drain electrode, disposed on thesemiconductor layer.
 3. The pixel structure according to claim 2,wherein the reflective structure comprises a first metallic layer. 4.The pixel structure according to claim 3, wherein the gate insulatinglayer extends outside the TFT and covers the first metallic layer. 5.The pixel structure according to claim 4, wherein the first metalliclayer is received in a depression of the substrate surface.
 6. The pixelstructure according to claim 3, wherein the gate insulating layerextends outside the TFT and is disposed between the first metallic layerand the transparent substrate.
 7. The pixel structure according to claim6, wherein the first metallic layer is received in a depression of thegate insulating layer surface.
 8. The pixel structure according to claim3, wherein the reflective structure further comprises a second metalliclayer, disposed on the first metallic layer.
 9. The pixel structureaccording to claim 8, wherein the gate insulating layer extends outsidethe TFT, and is disposed between the first metallic layer and the secondmetallic layer.
 10. The pixel structure according to claim 1, whereinthe reflective structure is sawtooth-shaped or block-shaped.
 11. Thepixel structure according to claim 1, further comprising a flattinglayer, disposed between the pixel electrode and the transparentsubstrate, and covering the TFT and the reflective structure.
 12. Afabricating method for fabricating a pixel structure for a transflectiveLCD panel, comprising: providing a transparent substrate; forming a TFTand configuring a reflective structure on the transparent substrate,wherein the reflective structure is located at one side of the TFT;forming a passivation layer over the transparent substrate, wherein thepassivation layer covers the TFT and the reflective structure; forming apixel electrode above the TFT and the reflective structure, wherein thepixel electrode and the TFT are electrically connected to each other;and forming a reflective layer above the TFT and the reflectivestructure.
 13. The fabricating method for fabricating a pixel structureaccording to claim 12, wherein the step of forming the TFT comprises:forming a gate electrode; forming a gate insulating layer, covering thegate electrode; forming a semiconductor layer on the gate insulatinglayer above the gate electrode; and forming a source/drain electrode onthe semiconductor layer, and coupling the semiconductor layer to thepixel electrode.
 14. The fabricating method for fabricating a pixelstructure according to claim 12, wherein the step of forming areflective structure comprises forming a first metallic layer on thetransparent substrate.
 15. The fabricating method for fabricating apixel structure according to claim 14, wherein the first metallic layeris formed simultaneously with the gate electrode.
 16. The fabricatingmethod for fabricating a pixel structure according to claim 15, whereinbefore the first metallic is formed, a first depression is formed forreceiving the first metallic layer.
 17. The fabricating method forfabricating a pixel structure according to claim 14, wherein the firstmetallic layer is formed simultaneously with the source/drain electrode.18. The fabricating method for fabricating a pixel structure accordingto claim 17, wherein after the gate insulating layer is formed andbefore the first metallic layer is formed, a second depression is formedon the gate insulating layer for receiving the first metallic layer. 19.The fabricating method for fabricating a pixel structure according toclaim 14, wherein the method for forming the reflective structurefurther comprises forming a second metallic layer on the first metalliclayer.
 20. The fabricating method for fabricating a pixel structureaccording to claim 19, wherein the first metallic layer and the gateelectrode are simultaneously formed, and the second metallic layer andthe source/drain electrode are simultaneously formed.
 21. Thefabricating method for fabricating a pixel structure according to claim20, wherein before forming the first metallic layer, a first depressionis formed for receiving the first metallic layer therein.
 22. Thefabricating method for fabricating a pixel structure according to claim20, wherein after the gate insulating layer is formed and before thesecond metallic layer is formed at the gate insulating layer, a seconddepression is formed for receiving the second metallic layer therein.23. The fabricating method for fabricating a pixel structure accordingto claim 18, wherein after the passivation layer formed and before thepixel electrode is formed, a flatting layer is formed over thetransparent substrate, covering the TFT and the reflective structure.